1. Field of the Invention
The present invention relates in general to computer networks and more particularly to an addressing method and system for allocating a local network address in favor of a remote network address. The local network address is a network address that resides in memory of a processor that is executing the process that is requesting the network address. The remote network address resides in memory of a different processor.
2. Related Art
Computer networks are widespread and vitally important to many types of enterprises including businesses, universities and government. In general, a computer network is two or more computers (or associated devices) that are connected by communication facilities. One type of computer network is a client/server computer network. The client/server computer network includes a server and one or more clients. The server is a computer that provides shared resources to users of the network. The client is a computer that users use to access the shared network resources provided by the server. The client accesses these network resources using the communication facilities. One example of a client/server computer network is the Internet (via the World Wide Web (WWW)). The Internet is a public wide area network (WAN) environment that enables remote clients to request and receive data from a server and access network resources (such as memory).
The server computer may include several different computers (called nodes). In addition, each node may contain multiple processors. Each node often has its own network resources that may be used by the processors on that node. One type of network resource is a network adapter card. A network adapter card transmits and receives information from the computer network. The network adapter card is used by a process executing on a processor to send or receive data from the network.
Some multi-node servers allow the network resources of each node to be shared among other nodes on the server. Thus, if a network resource on one node is being used an available network resource on another node may be used by a process. Sharing of network resources allows a process executing on any of the processors to access to any available a network resource on the multi-node server. By way of example, if a multi-node server has four nodes with a network adapter card on each node, a process executing on a node one processor could access any of the network adapter cards located on nodes one to four. Sharing of network resources has the advantage of decreasing wait time for a process trying to use a network resource.
Another network resource that may be shared in a multi-node server environment is memory. When memory is shared between processors, the memory is distributed so that each processor “owns” a portion of the total memory. In this distributed memory technique, the portion of the total memory that belongs to a specific processor is called local memory. The portion of the memory belonging to other processors is called remote memory. When memory is shared, a process executing on a processor can have access to both local memory and remote memory. This allows a processor that is using all of its local memory to access additional, remote memory so that the process running on the processor can continue processing.
In order to access a network resource a process must obtain a network address. The process requests the network address from an addressing server. In a multi-node server environment having shared resources, the local memory of each processor has stored therein a certain number of network addresses. For example, the local memory of a processor may contain six to eight network addresses. A list of the network addresses and their location in memory is maintained by the addressing server.
When allocating network addresses, current addressing techniques do not differentiate between network addresses residing in local memory or in remote memory. Local memory means memory that is owned by the processor executing the process that is requesting the network address. Remote memory means memory that is owned by another processor. These current addressing techniques allocate the next network address on the list when they receive a request for a network address from a process.
One problem, however, is that these current addressing techniques do not take into account whether the network address being assigned resides in local memory or remote memory. This is important, because access time to local memory is much shorter than access time to remote memory. Accordingly, the time to access a network resource increases or decreases depending upon which network address is assigned. If a local network address is allocated then access time is decreased. On the other hand, if a remote network address is allocated then access time increased.
By way of example, assume that a process is running on processor one, node one and needs to access the network. The process makes a request for a network address to the addressing server. Current addressing techniques will allocate the next network address on the list. If the network address happens to be located in the local memory of processor one, node one, then access time to the network will be faster than if the network address resides in memory of another processor.
This disparity in access times is because the process requesting the network adapter card is executing on processor one, node one, and therefore it is local when a network address residing in the memory of processor one, node one is assigned. On the other hand, when a network address residing in the memory of a different processor is assigned to the same process, the process must remotely access the memory of this remote processor. This increases the time required to access the network adapter card.
Therefore, what is needed is an addressing method and system using distributed memory that allocates a network address residing in local memory in favor of a network address located in remote memory. In particular, what is needed is an addressing method and system for assigning network addresses so that, to the extent possible, a network address located in local memory is allocated. Moreover, what further is needed is an addressing method and system for dynamically assigning network addresses helps to optimize network performance by facilitating local access to network resources by allocating local network addresses.